Background: Tripterygium wilfordii Hook F (TwHF) alone or in combination with methotrexate (MTX) has been shown to be more effective than MTX monotherapy in controlling the manifestations in subjects with disease-modifying antirheumatic drug (DMARD)-naïve active rheumatoid arthritis (RA) over a 6-month period. The long-term impact of these therapies on disease activity and radiographic progression in RA has not been examined.
Methods: Patients with DMARD-naïve RA enrolled in the "Comparison of Tripterygium wilfordii Hook F with methotrexate in the Treatment of Active Rheumatoid Arthritis" (TRIFRA) study were randomly allocated into three arms with TwHF or MTX or the two in combination. Clinical indexes and radiographic data at baseline and year 2 was collected and compared using an intent-to-treat (ITT) and a per-protocol (PP) analysis. Two radiologists blinded to the treatment scored the images independently.
Results: Of 207 subjects 109 completed the 2-year follow up. The number of subjects withdrawing from the study and the number adhering to the initial regimens were similar among the three groups (p > = 0.05). In the ITT analysis, proportions of patients reaching American College of Rheumatology 50% (ACR50) response criteria were 46.4%, 58.0% and 50.7% in the MTX, TwHF and MTX + TwHF groups (TwHF vs MTX monotherapy, p = 0.004). Similar patterns were found in ACR20, ACR70, Clinical Disease Activity Index good responses, European League Against Rheumatism good response, remission rate and low disease activity rate at year 2. The results of the PP analysis agreed with those in the ITT analysis. The changes in total Sharp scores and joint erosion and joint space narrowing during the 2 years were associated with changes in disease activity measured by the 28-joint count Disease Activity Score and were comparable among the three groups (p > 0.05). Adverse events were similar in the three treatment groups.
Conclusions: During the 2-year therapy period, TwHF monotherapy was not inferior to MTX monotherapy in controlling disease activity and retarding radiological progression in patients with active RA.
Trial registration: This is a follow-up study. Original trial registration: ClinicalTrials.gov , NCT01613079 . Registered on 4 June 2012.
Keywords: Radiological progression; Rheumatoid arthritis; Tripterygium wilfordii Hook F.